TSC1 binding to lysosomal PIPs is required for TSC complex translocation and mTORC1 regulation

Katharina Fitzian, Anne Brückner, Laura Brohée, Reinhard Zech, Claudia Antoni, Stephan Kiontke, Raphael Gasper, Anna Livia Linard Matos, Stephanie Beel, Sabine Wilhelm, Volker Gerke, Christian Ungermann, Mark Nellist, Stefan Raunser, Constantinos Demetriades*, Andrea Oeckinghaus*, Daniel Kümmel*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)

Abstract

The TSC complex is a critical negative regulator of the small GTPase Rheb and mTORC1 in cellular stress signaling. The TSC2 subunit contains a catalytic GTPase activating protein domain and interacts with multiple regulators, while the precise function of TSC1 is unknown. Here we provide a structural characterization of TSC1 and define three domains: a C-terminal coiled-coil that interacts with TSC2, a central helical domain that mediates TSC1 oligomerization, and an N-terminal HEAT repeat domain that interacts with membrane phosphatidylinositol phosphates (PIPs). TSC1 architecture, oligomerization, and membrane binding are conserved in fungi and humans. We show that lysosomal recruitment of the TSC complex and subsequent inactivation of mTORC1 upon starvation depend on the marker lipid PI3,5P2, demonstrating a role for lysosomal PIPs in regulating TSC complex and mTORC1 activity via TSC1. Our study thus identifies a vital role of TSC1 in TSC complex function and mTORC1 signaling.

Original languageEnglish
Pages (from-to)2705-2721.e8
JournalMolecular Cell
Volume81
Issue number13
DOIs
Publication statusPublished - 1 Jul 2021

Bibliographical note

Funding Information:
We are grateful to Andrea Bolle and Stefanie Kipschull for excellent technical assistance and Prof. Dr. Michael Meisterernst for his support. We thank Stefanie Albrecht for assistance with confocal immunofluorescence microscopy, the MPI-AGE FACS & Imaging Core Facility, Roger Scherres from Wyatt Technologies for help with MALS measurements, and Melissa Graewert for support during SAXS measurement at beamlines P12 at PETRA III, EMBL Hamburg, which received financial support from iNEXT (PID: 6377 ). We also thank the staff at beamlines P13 at PETRA III, EMBL Hamburg, and 14.1 at BESSY II, Berlin, for assistance during X-ray diffraction data collection and Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) for the allocation of synchrotron radiation beamtime, and we acknowledge the financial support by HZB . This work was supported by grants from Deutsche Forschungsgemeinschaft (DFG) to V.G. ( GE 514/6-3 and SFB 1348-A04 ), C.U. ( SFB 944-P11 ), D.K. ( KU 2531/2 , KU 2531/3 , and SFB 944-P17 ) and A.O. ( OE 531/2 ) and the Innovative Medical Research (IMF) Initiative of the University of Münster ( OE121701 ) to A.O. L.B. acknowledges support from the Boost! program of the Max Planck Society . S.R. is funded by the Max Planck Society . C.D. is funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement 757729 ) and by the Max Planck Society .

Funding Information:
We are grateful to Andrea Bolle and Stefanie Kipschull for excellent technical assistance and Prof. Dr. Michael Meisterernst for his support. We thank Stefanie Albrecht for assistance with confocal immunofluorescence microscopy, the MPI-AGE FACS & Imaging Core Facility, Roger Scherres from Wyatt Technologies for help with MALS measurements, and Melissa Graewert for support during SAXS measurement at beamlines P12 at PETRA III, EMBL Hamburg, which received financial support from iNEXT (PID: 6377). We also thank the staff at beamlines P13 at PETRA III, EMBL Hamburg, and 14.1 at BESSY II, Berlin, for assistance during X-ray diffraction data collection and Helmholtz-Zentrum Berlin f?r Materialien und Energie (HZB) for the allocation of synchrotron radiation beamtime, and we acknowledge the financial support by HZB. This work was supported by grants from Deutsche Forschungsgemeinschaft (DFG) to V.G. (GE 514/6-3 and SFB 1348-A04), C.U. (SFB 944-P11), D.K. (KU 2531/2, KU 2531/3, and SFB 944-P17) and A.O. (OE 531/2) and the Innovative Medical Research (IMF) Initiative of the University of M?nster (OE121701) to A.O. L.B. acknowledges support from the Boost! program of the Max Planck Society. S.R. is funded by the Max Planck Society. C.D. is funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement 757729) and by the Max Planck Society. K.F. A.B. L.B. R.Z. C.A. R.G. A.L.L.M. S.B. and S.W. performed research. K.F. A.B. L.B. R.Z. C.A. S.K. R.G. and A.L.L.M. analyzed data. V.G. C.U. S.R. C.D. A.O. and D.K. supervised research. M.N. provided reagents. C.D. A.O. and D.K. designed research. D.K. wrote the paper with contributions from all authors. The authors declare no competing interests.

Publisher Copyright:
© 2021 Elsevier Inc.

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